A light and electron microscopic study of recurrent granular dystrophy of the cornea.

Light and electron microscopic studies in three cases of recurrent granular dystrophy with corneal epithelial involvement showed intracellular rod and trapezoidal crystalline granules characteristic of granular dystrophy. Small intraepithelial cytoplasmic granules were rimmed by 15-nm particles, while larger deposits were often membrane-bound. The granules were closely associated with tonofilaments. There were ultrastructural similarities to keratohyaline. Extracellular granules were often intermixed with cytoplasmic organelles of disintegrated squamous epithelial cells. There was no evidence of a subepithelial pannus. These findings suggest an epithelial origin of the granular dystrophic deposits in these recurrent cases.